Over-acceleration in your swing short-circuits power. Over-acceleration prevents you from achieving maximum swing speed at or just after impact. With the best swings in the world, maximum swing speed comes a split second before impact.
Here is a Proven Swing Speed Drill
This drill that teaches you to achieve maximum speed just before impact.
Go to the driving range. Take out your driver. Grip it from the clubhead end. Now swing the club. Try to swing it so you hear the whoosh later in your swing. After doing this for a few minutes, hit some balls. Work on waiting until the club is at least halfway through the downswing before letting loose. Do this drill until your maximum swing speed is just be-fore impact
Watch the world’s best swings on tour. You’ll see that the follow-through usually takes less time than the backswing or the downswing. The drill described above trains you to speed up your swing just before impact.
